CAE Fidesys 9.0 Documentation

Standard Formulas of Time Dependencies

The preprocessor interface provides for setting the dependence of boundary conditions as follows:

• ready-made formulas from the list;

• user input of the dependency formula, where the arguments are time variable;

• tabular dependency assignment;

• plotting.

It is possible to set a piecewise constant function and a delta function.

Ready-made formulas from the list should include:

• explosive source;

• constant;

• Riker;

• Berlage;

• the first time derivative of Berlage;

• the second time derivative of Berlage.

Time dependence can be applied to all attached to the body boundary conditions: displacement, pressure, force, temperature, thermal flow, convection, velocity, acceleration. The user can select a boundary condition applied to the body in advance and set a time dependence on it in any of the ways described earlier.

Types of dependencies

Notation:

A is the amplitude;

ω is the frequency;

t is the time.

Formulas:

• Exponent

  , where α - attenuation coefficient;

• Riker

  ,
  where t₀ the moment when the maximum of the function is reached, a shift by pi in CAE Fidesys is necessary for the zero value of the function at the initial moment of time.

• Berlage

  , where
  .